Scrap metals are currently sorted at high speed or high volume using a conveyor belt or other line operations using a variety of techniques including: air sorting, vibratory sorting, color based sorting, magnetic sorting, hand sorting by a line operator, spectroscopic sorting, and the like. The scrap metals are typically shredded before sorting and require sorting to facilitate reuse of the metals. By sorting the scrap metals, metal is reused that may otherwise go to a landfill. Additionally, use of sorted scrap metal leads to reduced pollution and emissions in comparison to refining virgin feedstock from ore or plastic from oil. Scrap metals may be used in place of virgin feedstock by manufacturers if the quality of the sorted metal meets standards. The scrap metals may include types of ferrous and non-ferrous metals, heavy metals, high value metals such as nickel or titanium, cast or wrought metals, and other various alloys.
X-ray sorting technology has been used in the metal sorting industry to sort scrap metals. An x-ray sorter measures the transmitted x-rays through a piece of scrap metal using a dual energy detector. The detector is capable of measuring at least two different energy levels transmitted through the scrap metal. The sorting algorithm is based on the ratio of the two energy levels measured by the detector.